Oral spirochetes are among the bacteria that are considered to be part of the periodontopathic microflora. The numbers of spirochetes in periodontal lesions increase as the disease progresses and decrease with treatment. Our long term goal is to elucidate the role of oral spirochetes in periodontal disease. In order to accomplish this goal, conditions for the selective isolation and cultivation of representative oral spirochetes must be determined. Once this has been established the isolates will be characterized morphologically, physiologically, antigenically, and genetically. When an association between the disease process and specific spirochete types has been determined, the periodontopathic potential of these isolates will be studied. The specific aims of this proposal are: 1) Determine selective methods for the isolation and cultivation of representative oral spirochetes; 2) Morphological characterization of oral spirochetes; 3) Determination of major carbon source and identifying metabolic activities and % mol guanine + cytosine composition of DNA of selected oral spirochetes.